bu seriously, how can you test 22A@12V ?You need a laboratory equipment to do so, exactly what?

I'm not quite sure why you're laughing. Kettle elements, toaster elements, fan heaters and combinations of have all been used for dummy loads since long before I was born. 44 2400W 240V kettles in parallel will give you 0.545 Ohms which will give you 22A@12V. 50 odd 2000w fan heaters will do the same thing for less money.

Alternatively, 4 12V headlamp bulbs and a tail light bulb in parallel will do the same thing for much fewer devices to wrangle.If you are clever you'll use a couple of toaster elements and re-configure them to give you a much lower resistance so you need fewer of them, but still.

Not super cheap, but not break-the-bank expensive and you might find a used one.

A DC load is a good way because sometimes these can also do pulses and they are not a purely resistive load.A couple of high power resistors is also an option but ofcourse you can't regulate these very well.

I have a luxury: for a past customer, I designed and built a dual channel, 0-18V, +/-60A controlled source/load. So, of course I keep one on hand so I can test anything they can.

Test a 12V supply? No problem, plug it in and crank up the amps! Load voltage and current are displayed on meters.

If you aren't so fortunate, any random load resistance is helpful. If you need a lot cheap, try looking inside industrial hulks at the scrapyard -- there may be power resistors inside! However you do it, you'll want a collection of assorted values, so you can mix and match for whatever loads you like. Tip: use a resistor network calculator to find the optimum network for a given maximum load.

The down side is the longer length. This is why I mentioned the spiral and the conductive balls for shorting bar.

You need to think of two pipes or rods coiled in a flat spiral. You have an air gap between the two pipes or rods in the spiral. You can roll the ball around the spiral to adjust the resistance.

You can get a very long length in the form of the spiral.You could use steel for the rods/pipes. Smaller size increases resistance & also lets you have a greater length in same size spiral. Think of A 50 foot long rod/pipe in a spiral, not that large.

Now if you think, a conductive ball will have some contact resistance. You could have one ball be course adjust and more balls down the spiral giving a finer adjust.

And it is not hard to create the spiral. Just bend three rods between two plates. Remove extra rod when bent. Adjust starting point of one rod in center to get gap the total length.

The problem with the spiral is increased heat output the shorter the length used.

There are some options in between the high-end commercial load testers, and the low-end DIY resistive loads. Google for the SkyRC BD200 for example - a commercial product for discharge testing of batteries which will do 30A/200W and isn't terribly expensive.